This invention relates to vehicle emergency warning systems, and is more particularly directed to a radio system which is used for communicating a yellow flag, i.e., caution condition, from a race official to the drivers of race cars or other racing vehicles and closed loop race course.
In automobile racing, when a caution period is declared by a race official, a flagman (or several flagmen) will indicate this to the drivers by displaying a yellow flag. This is often supplemented by trackside caution lamps. This existing system has a number of drawbacks, which result in collisions and pile-ups that occur "under the yellow flag".
The existing system of flags and lights relies on a race competitor's seeing the flag or light at a time when he or she is concentrating completely on operating the race car. Because of the nature of the driving competition, it is often difficult for the drivers either to see the existing system or to react to it. One of the main pitfalls of the existing system is that, due to dust and smoke on the course, proximity to or distance from the existing system, or glare of sunlight in the eyes of the drivers, as well as the need to concentrate on the driving, competition drivers cannot all be expected to see the caution signal at the same time. Also, because a driver and race car may often have to complete an entire loop before passing under the flagman, many competitors take advantage of the first lap of a caution period by overtaking another car and bettering their position in the race. This, of course, is highly dangerous as the race car driver will often steer into the very same wrecked car that is the reason a caution was declared.
Also, the two existing systems, flagmen and lights, are not always initiated at the exact same time, and some of the drivers will rely on one or the other, but not both. Moreover, one competitor's view may often be blocked by another competitor's race car. In either case, if a competitor reacts to the caution, a closely-following competitor may not see the caution at the same time and not react, which can eventuate in a rear end collision that is costly and extremely dangerous for both competitors. This type of collision can result in serious injury or death.
Because of accidents of this type that can occur while "under the yellow", race promotors have experienced sharply increased cost for insurance, and race fans experience considerable delays in the race due to extra "clean up".
In short, the existing caution alerting systems for motor vehicle racing lack the ability to signal a caution warning to all the competitors simultaneously, and cannot ensure that the competitors will be alerted to the caution under all race conditions.